clang crashes in `Sema::ImpCastExprToType`

[ahatanak]

$ cat test.cpp

template <typename c> void d() {
  __typeof__(sizeof(c) <= 1) e;
  if (!e)
    ;
}

$ clang++ -std=c++20 -c test.cpp

can't implicitly cast glvalue to prvalue with this cast kind: NoOp
UNREACHABLE executed at /root/llvm-project/clang/lib/Sema/Sema.cpp:700!
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.	Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/clang++ -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -std=c++20 <source>
1.	<source>:3:9: current parser token ')'
2.	<source>:1:32: parsing function body 'd'
3.	<source>:1:32: in compound statement ('{}')
 #0 0x0000000003a36d28 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3a36d28)
 #1 0x0000000003a34a0c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3a34a0c)
 #2 0x000000000397a7a8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x000076b170442520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x000076b1704969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x000076b170442476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x000076b1704287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x000000000398617a (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x398617a)
 #8 0x0000000006548dfa clang::Sema::ImpCastExprToType(clang::Expr*, clang::QualType, clang::CastKind, clang::ExprValueKind, llvm::SmallVector<clang::CXXBaseSpecifier*, 4u> const*, clang::CheckedConversionKind) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6548dfa)
 #9 0x000000000699e92d clang::Sema::CreateBuiltinUnaryOp(clang::SourceLocation, clang::UnaryOperatorKind, clang::Expr*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x699e92d)
#10 0x000000000699ea8d clang::Sema::BuildUnaryOp(clang::Scope*, clang::SourceLocation, clang::UnaryOperatorKind, clang::Expr*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x699ea8d)
#11 0x0000000006437523 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6437523)
#12 0x000000000643a43a clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x643a43a)
#13 0x000000000643a5d9 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x643a5d9)
#14 0x000000000643efc9 clang::Parser::ParseExpression(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x643efc9)
#15 0x0000000006450c36 clang::Parser::ParseCXXCondition(clang::ActionResult<clang::Stmt*, true>*, clang::SourceLocation, clang::Sema::ConditionKind, bool, clang::Parser::ForRangeInfo*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6450c36)
#16 0x00000000064b4060 clang::Parser::ParseParenExprOrCondition(clang::ActionResult<clang::Stmt*, true>*, clang::Sema::ConditionResult&, clang::SourceLocation, clang::Sema::ConditionKind, clang::SourceLocation&, clang::SourceLocation&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64b4060)
#17 0x00000000064bcc86 clang::Parser::ParseIfStatement(clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64bcc86)
#18 0x00000000064b6563 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64b6563)
#19 0x00000000064b7c77 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64b7c77)
#20 0x00000000064b8a65 clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64b8a65)
#21 0x00000000064ba2ca clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64ba2ca)
#22 0x00000000063ce983 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63ce983)
#23 0x0000000006404718 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6404718)
#24 0x00000000064cb4f6 clang::Parser::ParseDeclarationAfterTemplate(clang::DeclaratorContext, clang::Parser::ParsedTemplateInfo&, clang::ParsingDeclRAIIObject&, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64cb4f6)
#25 0x00000000064d8c94 clang::Parser::ParseTemplateDeclarationOrSpecialization(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifier) (.part.0) ParseTemplate.cpp:0:0
#26 0x00000000064d8faa clang::Parser::ParseDeclarationStartingWithTemplate(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64d8faa)
#27 0x000000000640d3b3 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x640d3b3)
#28 0x00000000063c9381 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63c9381)
#29 0x00000000063ca22f clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63ca22f)
#30 0x00000000063ca6f0 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63ca6f0)
#31 0x00000000063bd9fc clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63bd9fc)
#32 0x0000000004323018 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4323018)
#33 0x00000000045aa249 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x45aa249)
#34 0x000000000453026e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x453026e)
#35 0x000000000469277e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x469277e)
#36 0x0000000000c709b5 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc709b5)
#37 0x0000000000c69bda ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#38 0x00000000043667b9 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#39 0x000000000397ac54 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x397ac54)
#40 0x0000000004366daf clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#41 0x000000000432c7f5 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x432c7f5)
#42 0x000000000432d25d clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x432d25d)
#43 0x0000000004334c75 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4334c75)
#44 0x0000000000c6dd85 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc6dd85)
#45 0x0000000000b45ff4 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xb45ff4)
#46 0x000076b170429d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#47 0x000076b170429e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#48 0x0000000000c6968e _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc6968e)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Akira Hatanaka (ahatanak)

$ cat test.cpp ``` template <typename c> void d() { __typeof__(sizeof(c) <= 1) e; if (!e) ; } ```

$ clang++ -std=c++20 -c test.cpp

can't implicitly cast glvalue to prvalue with this cast kind: NoOp
UNREACHABLE executed at /root/llvm-project/clang/lib/Sema/Sema.cpp:700!
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.	Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/clang++ -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -std=c++20 <source>
1.	<source>:3:9: current parser token ')'
2.	<source>:1:32: parsing function body 'd'
3.	<source>:1:32: in compound statement ('{}')
 #<!-- -->0 0x0000000003a36d28 llvm::sys::PrintStackTrace(llvm::raw_ostream&amp;, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3a36d28)
 #<!-- -->1 0x0000000003a34a0c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3a34a0c)
 #<!-- -->2 0x000000000397a7a8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #<!-- -->3 0x000076b170442520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #<!-- -->4 0x000076b1704969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #<!-- -->5 0x000076b170442476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #<!-- -->6 0x000076b1704287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #<!-- -->7 0x000000000398617a (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x398617a)
 #<!-- -->8 0x0000000006548dfa clang::Sema::ImpCastExprToType(clang::Expr*, clang::QualType, clang::CastKind, clang::ExprValueKind, llvm::SmallVector&lt;clang::CXXBaseSpecifier*, 4u&gt; const*, clang::CheckedConversionKind) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6548dfa)
 #<!-- -->9 0x000000000699e92d clang::Sema::CreateBuiltinUnaryOp(clang::SourceLocation, clang::UnaryOperatorKind, clang::Expr*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x699e92d)
#<!-- -->10 0x000000000699ea8d clang::Sema::BuildUnaryOp(clang::Scope*, clang::SourceLocation, clang::UnaryOperatorKind, clang::Expr*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x699ea8d)
#<!-- -->11 0x0000000006437523 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&amp;, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6437523)
#<!-- -->12 0x000000000643a43a clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x643a43a)
#<!-- -->13 0x000000000643a5d9 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x643a5d9)
#<!-- -->14 0x000000000643efc9 clang::Parser::ParseExpression(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x643efc9)
#<!-- -->15 0x0000000006450c36 clang::Parser::ParseCXXCondition(clang::ActionResult&lt;clang::Stmt*, true&gt;*, clang::SourceLocation, clang::Sema::ConditionKind, bool, clang::Parser::ForRangeInfo*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6450c36)
#<!-- -->16 0x00000000064b4060 clang::Parser::ParseParenExprOrCondition(clang::ActionResult&lt;clang::Stmt*, true&gt;*, clang::Sema::ConditionResult&amp;, clang::SourceLocation, clang::Sema::ConditionKind, clang::SourceLocation&amp;, clang::SourceLocation&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64b4060)
#<!-- -->17 0x00000000064bcc86 clang::Parser::ParseIfStatement(clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64bcc86)
#<!-- -->18 0x00000000064b6563 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector&lt;clang::Stmt*, 32u&gt;&amp;, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&amp;, clang::ParsedAttributes&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64b6563)
#<!-- -->19 0x00000000064b7c77 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector&lt;clang::Stmt*, 32u&gt;&amp;, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64b7c77)
#<!-- -->20 0x00000000064b8a65 clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64b8a65)
#<!-- -->21 0x00000000064ba2ca clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64ba2ca)
#<!-- -->22 0x00000000063ce983 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&amp;, clang::Parser::ParsedTemplateInfo const&amp;, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63ce983)
#<!-- -->23 0x0000000006404718 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&amp;, clang::DeclaratorContext, clang::ParsedAttributes&amp;, clang::Parser::ParsedTemplateInfo&amp;, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6404718)
#<!-- -->24 0x00000000064cb4f6 clang::Parser::ParseDeclarationAfterTemplate(clang::DeclaratorContext, clang::Parser::ParsedTemplateInfo&amp;, clang::ParsingDeclRAIIObject&amp;, clang::SourceLocation&amp;, clang::ParsedAttributes&amp;, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64cb4f6)
#<!-- -->25 0x00000000064d8c94 clang::Parser::ParseTemplateDeclarationOrSpecialization(clang::DeclaratorContext, clang::SourceLocation&amp;, clang::ParsedAttributes&amp;, clang::AccessSpecifier) (.part.0) ParseTemplate.cpp:0:0
#<!-- -->26 0x00000000064d8faa clang::Parser::ParseDeclarationStartingWithTemplate(clang::DeclaratorContext, clang::SourceLocation&amp;, clang::ParsedAttributes&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x64d8faa)
#<!-- -->27 0x000000000640d3b3 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&amp;, clang::ParsedAttributes&amp;, clang::ParsedAttributes&amp;, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x640d3b3)
#<!-- -->28 0x00000000063c9381 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&amp;, clang::ParsedAttributes&amp;, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63c9381)
#<!-- -->29 0x00000000063ca22f clang::Parser::ParseTopLevelDecl(clang::OpaquePtr&lt;clang::DeclGroupRef&gt;&amp;, clang::Sema::ModuleImportState&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63ca22f)
#<!-- -->30 0x00000000063ca6f0 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr&lt;clang::DeclGroupRef&gt;&amp;, clang::Sema::ModuleImportState&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63ca6f0)
#<!-- -->31 0x00000000063bd9fc clang::ParseAST(clang::Sema&amp;, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x63bd9fc)
#<!-- -->32 0x0000000004323018 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4323018)
#<!-- -->33 0x00000000045aa249 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x45aa249)
#<!-- -->34 0x000000000453026e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x453026e)
#<!-- -->35 0x000000000469277e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x469277e)
#<!-- -->36 0x0000000000c709b5 cc1_main(llvm::ArrayRef&lt;char const*&gt;, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc709b5)
#<!-- -->37 0x0000000000c69bda ExecuteCC1Tool(llvm::SmallVectorImpl&lt;char const*&gt;&amp;, llvm::ToolContext const&amp;) driver.cpp:0:0
#<!-- -->38 0x00000000043667b9 void llvm::function_ref&lt;void ()&gt;::callback_fn&lt;clang::driver::CC1Command::Execute(llvm::ArrayRef&lt;std::optional&lt;llvm::StringRef&gt;&gt;, std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt;&gt;*, bool*) const::'lambda'()&gt;(long) Job.cpp:0:0
#<!-- -->39 0x000000000397ac54 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref&lt;void ()&gt;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x397ac54)
#<!-- -->40 0x0000000004366daf clang::driver::CC1Command::Execute(llvm::ArrayRef&lt;std::optional&lt;llvm::StringRef&gt;&gt;, std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt;&gt;*, bool*) const (.part.0) Job.cpp:0:0
#<!-- -->41 0x000000000432c7f5 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&amp;, clang::driver::Command const*&amp;, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x432c7f5)
#<!-- -->42 0x000000000432d25d clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&amp;, llvm::SmallVectorImpl&lt;std::pair&lt;int, clang::driver::Command const*&gt;&gt;&amp;, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x432d25d)
#<!-- -->43 0x0000000004334c75 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&amp;, llvm::SmallVectorImpl&lt;std::pair&lt;int, clang::driver::Command const*&gt;&gt;&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4334c75)
#<!-- -->44 0x0000000000c6dd85 clang_main(int, char**, llvm::ToolContext const&amp;) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc6dd85)
#<!-- -->45 0x0000000000b45ff4 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xb45ff4)
#<!-- -->46 0x000076b170429d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#<!-- -->47 0x000076b170429e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#<!-- -->48 0x0000000000c6968e _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc6968e)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[shafik]

This looks like a regression from clang-18: https://godbolt.org/z/nh5sfTMhE

[shafik]

CC @sdkrystian I am wondering if this is related to 1595988

[ahatanak]

Reverting 1595988 fixes the crash.

[ahatanak]

@sdkrystian have you had a chance to take a look at the crash?

It looks like ImpCastExprToType is expecting the expression that is passed to be a prvalue.

Also the fix in 638867a would make the type of e non-dependent and fix the crash, but unfortunately the patch got reverted.

[sdkrystian]

@ahatanak I can look into it tomorrow

[sdkrystian]

@shafik @ahatanak I've reduced the provided code to the following:

template<bool B>
void f() {
  decltype(B) x = false;
  __typeof__(B) y = false;
  !x; // no crash
  !y; // crash
}

The reason for the difference is because for TypeOfExprType, we use a DependentTypeOfExprType as the canonical type when the operand is type dependent. For DecltypeType, we use a DependentDecltypeType as the canonical type when the operand is instantiation dependent. Since 1595988 changes Type::isOverloadableType to perform different checks based on whether the canonical type is dependent, I think the fix is to change it to check the dependent of the type itself rather than the canonical type. Alternatively, we could change getTypeOfExprType to use a DependentTypeOfExprType as the canonical type when the operand is instantiation dependent.